I'm beginning to think that LW needs some better mechanism for dealing with the phenomenon of commenters who are polite, repetitive, immune to all correction, and consistently wrong about everything.

Hmm. This seems like the easiest property to target. A community norm of being confrontational about this? Although, changing community norms might be significantly more difficult than adding a new mechanism.

That said, there seems to be a negative reaction to suggestions like this, and possibly these posters will give timtyler more leeway for a time - that being the obvious way to express displeasure at this concept. Maybe make it clear that the community can obviate the need for the mechanism by being more critical?